In reply to Aaron T. Pratt.

Thanks for this very useful reference, Aaron. The Magna Charta is #3594 in the Bright catalog. Here is the entire description: "Magna Charta, 12mo, R. Tottill, 1587, printed upon quarto paper, with a very large margin, and interleaved: a few MS. notes in the hand of the time. 4to". (Incidentally, the catalog at Duke has prices in manuscript; the Bright Magna Charta sold for 2 pounds, 2 shillings.)

Since the copy at Duke is not interleaved, it's certainly not the same copy, but the rest of the description does sound very similar. I assume that the catalog's "12mo" is used as a general size designation for the printed area in the catalog, rather than bibliographic format, as the printed signatures in the Duke copy match the octavo format of STC 9282.

Thanks again for this useful information!